Research into supplying energy using natural energy such as sunlight, solar heat, and wind power is being actively conducted due to issues of air pollution and fossil fuel exhaustion. Since an amount of sunlight as an energy source is limitless, a required amount of the sunlight is produced in a required place, and maintaining the sunlight is relatively easy. Thus, the sunlight may be used for various uses of an energy supply apparatus. In general, a sunlight energy supply apparatus may track a maximum power point (MPP) to extract a maximum power. An example of such conventional sunlight energy supply apparatus is illustrated in FIG. 1.
The conventional sunlight energy supply apparatus includes a solar cell 1, an MPP tracking power converter 2, an energy storage element 3, and a DC-DC power converter 4, and supplies a power to an external electronic circuit 5. When the solar cell 1 generates the power, the MPP tracking power converter 2 may control a voltage and a current to supply a maximum power. The power may be stored in the energy storage element 3, for example, a battery and a large capacitor, and supplied to the external electronic circuit 5 when necessary. Here, the voltage may be changed in and supplied by the DC-DC power converter 4 such that the voltage required in the external electronic circuit 5 may be supplied.
Concisely, the conventional sunlight supply apparatus includes the MPP tracking power converter 2 and the DC-DC power converter 4, and thus issues of increasing volume and manufacturing costs of the sunlight supply apparatus may arise.
Such issues may arise when a power converter is included, in relation to generation that may not be limited to sunlight generation.
FIG. 2 illustrates an example of a conventional energy supply apparatus of which an energy source is a general energy source. The conventional energy supply apparatus of FIG. 2 includes an energy extractor 6, a rectifier 7, the DC-DC power converter 4, a controller 8, and the energy storage element 3, and supplies a power to an external load 9. The energy extractor 6 may be the aforementioned solar cell, and may be provided in various forms, for example, a piezoelectric element and a thermoelectric element, according to a type of an energy source. The rectifier 7 is a selective configuration for converting an alternating current generated in the energy extractor 6 to a power of a direct current. The DC-DC power converter 4 stores energy in the energy storage element 3 by converting a power to a desired power of a direct current voltage according to a control of the controller 8. A power converter is also a required part of the energy supply apparatus of FIG. 2, and thus the issues of increasing volume and manufacturing costs of the energy supply apparatus may arise.